Caption from LIFE. "Learning how to tell, 1,000 women in Elmhurst, Illinois, watch American Cancer Society's film on detection routine, Breast Self-Examination. In seven years 6.5 million women have seen it." NOTE: This image is a composite of two photos, with the "onscreen" picture literally taped on to the other of the film audience.

Angelina Jolie’s bombshell announcement that she underwent a preventive double mastectomy in hopes of minimizing her risk of breast cancer still has, understandably, an awful lot of people talking. Some commentators have suggested that Jolie’s action and, more importantly, the powerful, public way that she let the world know of her decision — on her own schedule, in her own words — could end up saving lives, if only because so many women who might have put off testing for years are now avidly searching for all the information they can find on breast cancer.

Of course, guarded optimism (and open pessimism) in the face of cancer is hardly new. Or rather, the last half century or so has seen truly extraordinary strides in treatment of myriad types of the disease. Sixty-five years ago, in May 1958, LIFE magazine published a cover story that considered an arsenal of new medical, technological and chemical approaches to diagnosis and treatment — approaches, the magazine suggested, that might do away with some cancers within the lifetime of those then fighting them.

The article, titled titled, “Cancer — on Brink of Breakthroughs,” put it this way to LIFE’s millions of readers:

It is a bad way to die and its name has long struck fear in human hearts. Fifty years ago a diagnosis of cancer was literally a sentence of death. No longer is that true, but in 1958 it will kill 250,000 Americans. [That number has more than doubled in the past 65 years. Last year, the American Cancer Society released a report stating that “in 2012, about 577,190 Americans are expected to die of cancer, more than 1,500 people a day. Cancer is the second most common cause of death in the US, exceeded only by heart disease, accounting for nearly 1 of every 4 deaths. — Ed.]

But within the lifetime of men living today the devastation will slacken. In act, if all the tools and techniques known today could be put into universal use overnight, one of every two victims could now be fully cured. Already these methods save one in three.

The facts about cancer are tangled in superstition and rumor. False news of miracle cures are always on the wind. As victims lose faith in medical help, as many as a fourth of the gravely ill fall prey to deluded or dishonest quacks.

Some of the photos in this gallery, meanwhile, will no doubt surprise and even shock contemporary readers. Prisoners injected with cancerous cells in order to test patient’s resistance to some cancers after exposure? Obviously, testing (of drugs, surgeries, exposure to pathogens, etc.) on both animals and on humans has always been a central component of the practice of medicine. But rarely does one see as graphic a representation of the way such tests were conducted in the middle part of the last century as in some of the pictures in this gallery.